detach -> release

The C++ standard library uses the name "release" for the operation we call "detach".

Rewriting each "detach(" to "release(" brings us a step closer to using standard library types directly (e.g. std::unique_ptr instead of SkAutoTDelete).

This was a fairly blind transformation.  There may have been unintentional conversions in here, but it's probably for the best to have everything uniformly say "release".

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1809733002

Review URL: https://codereview.chromium.org/1809733002
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index dd792dd..88dd74f 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -647,7 +647,7 @@
             }
         } while(SkCommandLineFlags::ShouldSkip(FLAGS_sourceType, fSourceType) ||
                 SkCommandLineFlags::ShouldSkip(FLAGS_benchType,  fBenchType));
-        return bench.detach();
+        return bench.release();
     }
 
     Benchmark* rawNext() {
@@ -665,7 +665,7 @@
             if (gm->runAsBench()) {
                 fSourceType = "gm";
                 fBenchType  = "micro";
-                return new GMBench(gm.detach());
+                return new GMBench(gm.release());
             }
         }